/* Plugin for jQuery for working with colors.
 *
 * Version 1.1.
 *
 * Inspiration from jQuery color animation plugin by John Resig.
 *
 * Released under the MIT license by Ole Laursen, October 2009.
 *
 * Examples:
 *
 *	$.color.parse("#fff").scale('rgb', 0.25).add('a', -0.5).toString()
 *	var c = $.color.extract($("#mydiv"), 'background-color');
 *	console.log(c.r, c.g, c.b, c.a);
 *	$.color.make(100, 50, 25, 0.4).toString() // returns "rgba(100,50,25,0.4)"
 *
 * Note that .scale() and .add() return the same modified object
 * instead of making a new one.
 *
 * V. 1.1: Fix error handling so e.g. parsing an empty string does
 * produce a color rather than just crashing.
 */

(function($) {
	$.color = {};

	// construct color object with some convenient chainable helpers
	$.color.make = function (r, g, b, a) {
		var o = {};
		o.r = r || 0;
		o.g = g || 0;
		o.b = b || 0;
		o.a = a != null ? a : 1;

		o.add = function (c, d) {
			for (var i = 0; i < c.length; ++i)
				o[c.charAt(i)] += d;
			return o.normalize();
		};
		o.scale = function (c, f) {
			for (var i = 0; i < c.length; ++i)
				o[c.charAt(i)] *= f;
			return o.normalize();
		};
		o.toString = function () {
			if (o.a >= 1.0) {
				return "rgb("+[o.r, o.g, o.b].join(",")+")";
			} else {
				return "rgba("+[o.r, o.g, o.b, o.a].join(",")+")";
			}
		};

		o.normalize = function () {
			function clamp(min, value, max) {
				return value < min ? min: (value > max ? max: value);
			}
			o.r = clamp(0, parseInt(o.r), 255);
			o.g = clamp(0, parseInt(o.g), 255);
			o.b = clamp(0, parseInt(o.b), 255);
			o.a = clamp(0, o.a, 1);
			return o;
		};

		o.clone = function () {
			return $.color.make(o.r, o.b, o.g, o.a);
		};

		return o.normalize();
	}

	// extract CSS color property from element, going up in the DOM
	// if it's "transparent"
	$.color.extract = function (elem, css) {
		var c;
		do {
			c = elem.css(css).toLowerCase();
			// keep going until we find an element that has color, or
			// we hit the body
			if (c != '' && c != 'transparent')
				break;
			elem = elem.parent();
		} while (!$.nodeName(elem.get(0), "body"));

		// catch Safari's way of signalling transparent
		if (c == "rgba(0, 0, 0, 0)")
			c = "transparent";
		return $.color.parse(c);
	}
	// parse CSS color string (like "rgb(10, 32, 43)" or "#fff"),
	// returns color object, if parsing failed, you get black (0, 0,
	// 0) out
	$.color.parse = function (str) {
		var res, m = $.color.make;

		// Look for rgb(num,num,num)
		if (res = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(str))
			return m(parseInt(res[1], 10), parseInt(res[2], 10), parseInt(res[3], 10));
		// Look for rgba(num,num,num,num)
		if (res = /rgba\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str))
			return m(parseInt(res[1], 10), parseInt(res[2], 10), parseInt(res[3], 10), parseFloat(res[4]));
		// Look for rgb(num%,num%,num%)
		if (res = /rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(str))
			return m(parseFloat(res[1])*2.55, parseFloat(res[2])*2.55, parseFloat(res[3])*2.55);

		// Look for rgba(num%,num%,num%,num)
		if (res = /rgba\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str))
			return m(parseFloat(res[1])*2.55, parseFloat(res[2])*2.55, parseFloat(res[3])*2.55, parseFloat(res[4]));
		// Look for #a0b1c2
		if (res = /#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(str))
			return m(parseInt(res[1], 16), parseInt(res[2], 16), parseInt(res[3], 16));

		// Look for #fff
		if (res = /#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(str))
			return m(parseInt(res[1]+res[1], 16), parseInt(res[2]+res[2], 16), parseInt(res[3]+res[3], 16));

		// Otherwise, we're most likely dealing with a named color
		var name = $.trim(str).toLowerCase();
		if (name == "transparent")
			return m(255, 255, 255, 0);
		else {
			// default to black
			res = lookupColors[name] || [0, 0, 0];
			return m(res[0], res[1], res[2]);
		}
	}
	var lookupColors = {
		aqua:[0,255,255],
		azure:[240,255,255],
		beige:[245,245,220],
		black:[0,0,0],
		blue:[0,0,255],
		brown:[165,42,42],
		cyan:[0,255,255],
		darkblue:[0,0,139],
		darkcyan:[0,139,139],
		darkgrey:[169,169,169],
		darkgreen:[0,100,0],
		darkkhaki:[189,183,107],
		darkmagenta:[139,0,139],
		darkolivegreen:[85,107,47],
		darkorange:[255,140,0],
		darkorchid:[153,50,204],
		darkred:[139,0,0],
		darksalmon:[233,150,122],
		darkviolet:[148,0,211],
		fuchsia:[255,0,255],
		gold:[255,215,0],
		green:[0,128,0],
		indigo:[75,0,130],
		khaki:[240,230,140],
		lightblue:[173,216,230],
		lightcyan:[224,255,255],
		lightgreen:[144,238,144],
		lightgrey:[211,211,211],
		lightpink:[255,182,193],
		lightyellow:[255,255,224],
		lime:[0,255,0],
		magenta:[255,0,255],
		maroon:[128,0,0],
		navy:[0,0,128],
		olive:[128,128,0],
		orange:[255,165,0],
		pink:[255,192,203],
		purple:[128,0,128],
		violet:[128,0,128],
		red:[255,0,0],
		silver:[192,192,192],
		white:[255,255,255],
		yellow:[255,255,0]
	};
})(jQuery);
